Sand-blasting nozzle.



erica.

JOHN P. WALSH, OF BGSTON, MASSACHUSETTS.

SAND-BLASTING NOZZLE. i j

amaca.

Application filed'September 1, 1909.

To all whom it may concern:

Be it known that I, JOHN I. WALSH, a citizen of the United States, and aresident of Boston, in the county of Suffolk and Commonwealth ofMassachusetts, have invented an Improvement in Sand-Blasting Nozzles, ofwhich the followingV description, in connection with the accompanyingdrawings, is a specification, like letters on the drawings representinglike parts.

This invention relates to sand blasting nozzles.

In order that the principles of the invention may be readily understoodI have disclosed certain embodiments thereof in the accompanyingdrawings, wherein- Figure l is a front end elevation of a sand blastingnozzle embodying my invention; Fig. 2 is a side elevation thereof; Fig.3 is a vert-ical longitudinal section thereof; Figs. t and 5 arevertical longitudinal sectional views of modified forms of my invention;Fig. 6 is a longitudinal section of a further modified form of myinvention; and Figs. 7 and 8 are respectively an end elevation and alongitudinal vert-ical section of still another form of my invention.

So far as I am aware, sand blasting nozzles heretofore constructed havebeen provided with but aV single discharge opening, thus restricting thecapacity of the device, as without movement of the nozzle only a verylimited surface area can be treated, thus rendering the action of thedevice slow and arduous.

In the course of my experiments I have ascertained that by providingasand blasting nozzle with a series of discharge openings so arranged asto discharge the sand against the surface to be cleaned in an unbrokensheet, I am enabled not only to `treat or operate upon a larger surfacearea without movement of the nozzle, but that at the saine time I canmore effectively discharge the sand blast against the treated surface. Ihave also discovered that by providing a plurality of discharge openingsI can greatly economize power and air.

Referring more particularly to the drawings and first to the formthereof shown in Figs. l, 2 and 3, the nozzle body is represented at l,it being of any suitable material. such, for example, as cast iron,steel, glass or rubber. One end of the nozzle is preferably threaded asindicated at 2, for

Specification of Letters Patent.

Patented Apr. 25, 1911.

Serial No. 515,662.

attachment to the usual hose which is in communication with the sourceof supply. Preferably the nozzle is provided with a narrow, elongateddischarge end, as represented most clearly at 3 in Fig. 2. In said end Iform a plurality of discharge open ings, four being shown in Figs. l and3. Said openings are preferably placed in alineinent and sufficientlyclose together to effect the discharge of the sand in a sheet againstlthe surface to be cleaned.

As illustrative of the principles of my invention, I may state that Ihave ascertained that a sand blasting nozzle having a single dischargehole three quarters of an inch in diameter and requiring the expenditureof between fifty and sixty horse power generating 522 cubic feet of airper minute at fifty pounds gage pressure will cut a swath less than twoinches in width, whereas if I employ four discharge holes, each threesixteenths of an inch in diameter, and therefore aggregating in diameterthree quarters of an inch, it is necessary to employ but 160 cubic feetof air per minute at lifty pounds gage pressure, the width of theresulting swath being between four and five inches. In other words,whereas 522 cubic feet of air per minute at fifty pounds gage pressurehave been heretofore employed in the use of nozzles having a singledischarge hole three-quarters of an inch in diameter and cutting a twoinch swath, I may by the use of the same amount of air utilize more thanthree nozzles constructed in accordance with my invention and cuttingswaths having the combined width of seventeen inches. These figures aregiven merely as illustrative of the results secured by the use of myinvention, it being understood that for other sizes of openings.corresponding savings are made in air and pressure as well as in horsepower. In other words, in the use of a single discharge hole of enlargeddiameter there is a very material loss of air and pressure. rI`here is asubstantially proportionate loss of air and pressure in the use ofsingle discharge openings of other diameters. Sand can be moreeffectively discharged through a small opening than through one oflarger diameter, so far as comparative efficiency of the two openings isconcerned, and aside from the relative volumes, but, owing to the smallarea that can be covered or cleaned by the use of a nozzle having asingle small' opening, it has been customary heretofore, to employ anozzle of larger diameter, with the result that more rapid but inferiorwork has been produced, even though a larger volume of sand has beendischarged in a given unit of time. Ivloreover, in the use of a singledischarge hole the result has been the production of mottled ornon-uniform work, inasmuch as the area covered by the use of a nozzlehaving a single opening is restricted and the user, in order to treatthe wall or other material as rapidly as possible, skips over portionsthereof from time to time, between successive paths as he moves thenozzle over the work.

By the use of a nozzle having a single opening of, say three-sixteenthsof an inch diameter, the width of surface that can be effectivelytreated thereby at any period of time is between one-half and threequarters of an inch, whereas by the use of four holes, aggregating thesaine diameter, and requiring, as previously stated, less power and air,the width of material effectively treated is increased to between fourand five inches. By increasing the width of surface that may be treatedat one time the workman can readily overlap the several swaths or pathsof treatment, so as to produce uniform work, without loss of eliiciencyor time. Moreover, in the use of a plurality of discharge holes Ipreferably employ means to divide and even in cases to subdivide the airand the sand, so that they `are directed to the ultimate point ofdischarge without loss of eiiiciency and without pocketing. Moreover,the nozzle is preferably tapered toward the discharge openings, therebyconcentrating the air blast and increasing its effectiveness.

In Fig. 3 I have shown four discharge openings a Z) c CZ, and haveprovided a main partition 4, preferably extending rearward closelyadjacent the screw threads 2 and minor partitions 5, G, by which thesand and air divided by the partition 4 are subdivided and directed tothe several discharge holes a b c and d. It will be apparent that theinterior of the nozzle is not provided with pockets or formations inwhich the sand can collect, but that the sand is directed at once to theseveral points of discharge and that the sand is discharged in anunbroken sheet against the work. As shown most clearly in Fig. 2, thenozzle is tapered from substantially the point 7 forwardly so that theair and sand are concentrated as stated. The several partitions 4, 5 and6 terminate rearwardly, that is, toward the inlet end 2 in thin or finlike edges, so as to present substantially no obstruction to the on rushof the sand.

It is apparent that the nozzle and its partitions may be of any suitableshape. In Fig. 4 I have also shown four discharge For certain form ofwork, as for example in cleaning castings, I arrange the openingsrotherwise than in alinement, as for example in a triangulararrangement, as shown at 12, Figs. 7 and S. The nozzle is provided withan inlet, and an outlet in free discharging relation to the inlet. Theoutlet, constituted by the forward portion of the nozzle, is providedwith a series of discharging passages or openings, as illustrated, bythe partition or partitions extending to the outlet and suflicientlytoward the forward end of the nozzle to effect the purposes stated.

From the foregoing description it is clear that in the use of a sandblasting nozzle embodying my invention there is a saving not only ofgage pressure but also of free air and that the resulting work is moreuniform in character. Moreover, the surface under treatment can be farmore rapidly cleaned.

I-Iaving thus described my invention, I desire it to be understood thatalthough specific terms are employed they are used in a descriptive andgeneric sense, and not for purposes of limitation the scope of myinvention being set forth in the following claims.

1. A sand blasting nozzle having one .end formed as an air inlet for thecombined admission of sand and the motive liuid and for attachment to adistributing hose, said nozzle having an outlet in free dischargingrelation to said inlet, and one or more longitudinally rangingpartitions between said inlet and outlet and extending to and dividingthe outlet into a series of discharge passages.

2. A sand blasting nozzle having a combined sand and motive Huid inletand a plurality of discharge passages, the inner surface of said nozzlegradually merging from the inlet end into said plurality of dischargepassages, and said passages being spaced from each other at said inletend by a fin like edge or edges, whereby pocketing of the sand isprevented.

3. A sand blasting nozzle having a com: bined sand and motive fluidinlet and a plurality of discharge passages, said passages beingseparated by partitions whose inner ends terminate at differentdistances from the inlet end of the nozzle, whereby the sand and motivefluid are progressively divided.

4. A sand blasting nozzle having an end formed as an air inlet for thecombined adoutlet and sub dividing the said divided 1 0 mission of sandand -a motive fluid and for niain stream.

attachment to a distributing hose, said noz- In testimony whereof, Ihave signed my Zle having a central partition extending tonaine to thisspecification, in the presence of Ward the outlet and having its inneredge i two subscribing Witnesses. directed toward the inlet, therebyequally to l JOHN P. WALSH. divide the stream of sand and niotive fluid,l Vitnesses: yand a partition upon each side of said cen- IRVING U.TOWNSEND, tral partition and also extending toward the i MAY H. LOWRY.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, D. C.

